Long-term down-regulation does not improve pregnancy rates in an in vitro fertilization program

Objective: To investigate the effects of long-term down-regulation (4 months) used in combination with gonadotropin ovarian stimulation for IVF-ET. Design: Prospective randomized study. Setting: Assisted Reproduction Unit of the Hospital Clinic i Provincial in Barcelona, a tertiary care setting. Patient(s): Thirty pairs of IVF patients who were matched for age, indication for IVF, and number of attempts. Intervention(s): Women were randomized to receive a standard long protocol of SC leuprolide acetate (n = 30, group L) or a monthly injection of leuprolide acetate depot for 4 months (n = 30, group D) before gonadotropin stimulation. Main Outcome Measure(s): Ovarian response and IVF outcome. Result(s): Days of ovarian stimulation, follicular recruitment and growth during gonadotropin treatment, and the endometrial thickness on the day of hCG administration were similar for the 2 groups of NF patients. However, the serum concentration of E-2 was significantly higher in group L even though group D received a higher total dose of gonadotropins. The number of follicles punctured, the number of oocytes retrieved, the number of oocytes fertilized, the number of embryos suitable for replacement and cryopreservation, the number of patients with ET, and implantation and clinical pregnancy rates were similar for groups L and D. However, the percentage of metaphase II oocytes was significantly higher in group L than in group D. Conclusion(s): Long-term down-regulation does not improve pregnancy rates in a general IVF program. (Fertil Steril(R) 1998;70:46-51. (C)1998 by American Society for Reproductive Medicine.).